This is what i was asking for when I requested that a feature be added where we could have multiple book sopen at once on the eink side, with tabs so you can switch easily and quickly between the books. Also, multiple page view on the eink side (after we get landscape mode, of course, since it is impractical in portrait mode) would be great. I've seen this on the NookStudy and it works great. You can have multiple pages open in the same book side by side (their reasoning was so that when you're working in a book that has solutions in the back you can have the problems on one page and the solutions on the other without having to flip back and forth, but it has other uses too), or you can have pages from different books open side by side.

This is what I'd personally really like to see. I asked about these features once, but I was told there wasn't enough of a demand.